Whether it’s a bright lager, a golden-orange pale ale, or a dark, rich stout, you’ve probably noticed that beers come in a wide range of colours. But have you wondered the same about their bottles?
Have you ever stopped to think why stouts usually come in brown bottles, while lagers and pilsners come in green ones?
In this article, we’ll break down the science behind why some beer bottles are brown, green, or clear. But first things first, to understand the story of coloured bottles, we need to take a look at the beer making process.
The beer making process
Beer isn’t just an alcoholic beverage, but a truly crafted experience. It’s produced through a process called brewing, using four key ingredients: barley, hops, yeast, and, of course, water.
The beer making process begins well before brewing, with the preparation of the grain. In the malting stage, barley and other grains are soaked, allowed to germinate and then dried, creating something called malt.
It’s not until the malt reaches the brewery, that the brewing process kicks-off. During milling, malt is broken down into small particles, which are then mixed with water (the mashing phase). This produces a sweet liquid (called wort) which is then boiled with hops – giving beer its unique flavours, bitterness and aromas.
After boiling, the mix is cooled and combined with yeast during fermentation. Here sugars are converted into alcohol and carbon dioxide, giving beer its characteristic fizziness. As flavours and aromas develop over time, the beer goes through maturation, which varies depending on the style and intended intensity.
After this maturation period, beer gets filtered clarity and smoothness, and, in some cases, sometimes carbonated. Final step is packaging this liquid gold into glass bottles, which preserve beer’s taste and aroma for longer.
The different types of beer
Ales
One key difference between ales and lagers comes down to yeast and fermentation temperature. Ales prefer warmer environments, so the yeast floats at the surface while fermenting. Their taste can range from fruity to earthy, but because of the fermentation style, ales tend to be stronger and slightly sweeter. Ales usually come in brown bottles, which help protect their flavour and aroma. They’re your go-to choice for a cosy and quiet evening, when you can savour it with the time it deserves.
Lagers
Lagers are the most popular beer style, usually known for being crisp, clean, and refreshing. Unlike ales, the yeast in lagers ferments at the bottom and at lower temperatures, giving them a smoother, lighter profile. They often come in brown or green bottles and are the perfect choice for quenching your thirst on a hot summer day.
Stouts and Porters
Stouts are typically darker brown beers, and a fun secret is that they’re actually ales — the only difference is that their malt just roasts for longer. These dark ales often come in brown bottles and give off chocolate, caramel, and coffee notes. They’re perfect for colder days and can help lift your wintery mood.
Other styles
From fruit beers to radlers, to non-alcoholic options, which are also becoming more and more popular, beer styles and nuances are endless. What we’ve covered here is really just the tip, or should we say ‘sip’ of the iceberg.
But after all, what’s the deal with bottle colours? Well, you might have guessed it: different beer types also usually come in different bottle colours, and there are three main reasons for this, which we explore next.
Why are beer bottles green, brown or clear – and why does it matter?
Beer bottle colours aren’t just about aesthetics – they can help preserve beer’s flavour, aroma and quality for longer. Whether a bottle is brown, green, or clear will influence how it holds up over time, how much light can get through, and even reflects historical or regional traditions.
Preserving flavour and aroma
Glass is a natural protector when it comes to keeping beer’s flavours and aromas as originally intended. It’s not by chance that glass has also been long used to store carbonated drinks and wine.
Because it’s a single-layered material, glass doesn’t require any chemical liners that could interfere with the beer. It also blocks oxygen from sneaking in and making your beer go stale (better to brew safe than sorry).
Whether a bottle is green or brown doesn’t directly affect taste, but it does control how much sunlight gets in — and that can make all the difference.
Protecting from light damage
Light exposure is one of the main threats to beer. When beer sits in the sun for too long, sensitive hop compounds break down and react with the proteins, releasing an unpleasant “skunky” smell.
This is why most beer bottles are brown or green. Brown (amber) bottles are the most effective, blocking up to 99.9% of UV rays, retaining beer’s top-notch flavour for months on end.
Marketing and historical tradition
If brown bottles are so effective, why are green and clear bottles still used? The answer often lies in marketing and history.
After World War II, when brown glass was in short supply, European breweries began using green bottles. Over time, green bottles became associated with premium brands and higher quality. Clear bottles, on the other hand, are often used for marketing purposes, so that consumers can see the beer inside before committing to buying it.
While brown bottles have historically been the standard for storing beer, green and clear bottles have become part of brands’ identities. It just goes to show how colours, labels, and overall design can really enhance brands’ value.
Now that you know the science (and history) behind coloured bottles, you can impress your friends whenever someone asks, “Why are beer bottles green or brown?”
You can say that it all comes down to three intertwined factors: flavour and aroma, light protection and tradition.
So next time you crack open a cold beer, remember that brown or green glass isn’t just a random choice, but a crucial one!
Related posts
Why is wine stored in glass?
Glass bottles remain the best choice for wine lovers. New research showed that 94% of consumers in France prefer glass wine bottles over other packaging materials, such as bag-in-box. But why is it that we think of glass when we think of wine? Or why do we often store them horizontally? And are wine bottles sustainable?
7 min
What is the difference between glass and crystal?
All crystal is glass, but not all glass is crystal. How does that work? In this article, we will explain all the differences and similarities between these two versatile materials.
4 min